Exergetic evaluation of gas-turbine based combined cycle system with vapor absorption inlet cooling

The aim of this study is to perform an exergetic evaluation of a gas-steam combined cycle power utility that is integrated with vapor absorption inlet air cooling system. Effect of several thermodynamic parameters on component-level and total exergy destruction are discussed. A detailed breakdown of exergy destruction in the cycle has been presented along with useful recommendations to improve exergy based cycle performance. The integration of inlet air cooling has been observed to increase exergy efficiency of combined cycle beyond a turbine inlet temperature of 1650 K. The combustor has been identified as the greatest source of irreversibility with highest exergetic improvement potential. The total exergy destruction for the cycle has been observed to reduce with increase in turbine inlet temperature (TIT) and decrease in compressor inlet temperature (TIC). At higher compressor pressure ratio (βcomp), except combustor all other components of topping cycle has been observed to suffer an increase in exergy destruction where as exergy destruction has been observed to reduce for all bottoming cycle components except the stack. The summation of exergy destruction of all cycle components is observed to be reduced at lower ambient relative humidity and lower ambient temperature.